KR102521637B1 - Hermetic compressor and control method thereof - Google Patents

Abstract

An airtight container in which a lower shell and an upper shell are coupled to form an airtight space therein according to an aspect of the present invention; a compression unit accommodated in the closed space and compressing the refrigerant; a driving motor providing a driving force to the compression unit; and a controller controlling the driving motor, wherein the controller controls the driving motor to decrease the RPM of the driving motor when the variation range of the current of the driving motor is greater than or equal to a preset reference variation range for a predetermined reference time. A hermetic compressor controlling the motor may be provided.

Description

Hermetic compressor and its control method {HERMETIC COMPRESSOR AND CONTROL METHOD THEREOF}

The present invention relates to a hermetic compressor and a control method thereof.

In general, a hermetic compressor is a device that receives power from a power generating device such as an electric motor or a turbine and compresses air, refrigerant, or other various working fluids by reciprocating motion of a piston to increase the pressure of the working fluid. Such hermetic compressors are widely used in household appliances such as refrigerators and air conditioners or throughout the industry.

Compressors mounted in refrigeration systems also tend to be applied with hermetic compressors capable of operating in a wide frequency band from a low operating frequency band below the commercial power frequency to a high operating frequency band above the commercial power frequency in order to realize high efficiency.

On the other hand, when the temperature and load in the refrigeration system in which the hermetic compressor is mounted change rapidly, the load may fluctuate intermittently, and a phenomenon in which the load fluctuates is called hunting. When such a hunting phenomenon occurs, there is a problem that the refrigerating capacity of the refrigeration system may decrease.

The present invention has been invented in view of the above background, and an object of the present invention is to provide a hermetic compressor capable of eliminating hunting and a control method thereof.

An airtight container in which a lower shell and an upper shell are coupled to form an airtight space therein according to an aspect of the present invention; a compression unit accommodated in the closed space and compressing the refrigerant; a driving motor providing a driving force to the compression unit; and a controller controlling the driving motor, wherein the controller controls the driving motor to decrease the RPM of the driving motor when the variation range of the current of the driving motor is greater than or equal to a preset reference variation range for a predetermined reference time. A hermetic compressor controlling the motor may be provided.

In addition, a hermetic compressor may be provided in which the controller controls the drive motor so that the reduced RPM of the drive motor is maintained at a preset set RPM for a predetermined set time.

In addition, the controller, when the change range of the current of the drive motor is lower than the reference change range after the set time has elapsed, the RPM of the drive motor is increased to the RPM before the RPM of the drive motor is decreased. A hermetic compressor controlling the drive motor to be driven may be provided.

In addition, a hermetic compressor may be provided in which the reference time is 15 seconds or more and 25 seconds or less, and the reference change width is ± 65 mA or more and ± 75 mA or less.

In addition, a driving step in which a driving motor included in the hermetic compressor is driven to compress the refrigerant; a change width determination step in which the controller determines whether the change range of the current of the driving motor is greater than or equal to a preset reference change range for a predetermined reference time; and an RPM reduction step of reducing the RPM of the drive motor to a preset set RPM when the change range of the current of the drive motor is greater than or equal to the reference change range during the reference time period. can

In addition, a hermetic compressor control method may be provided in which the driving motor includes a three-phase motor, and in the step of determining the variation range, the controller determines the variation range through a current of one of the three phases of the motor.

In addition, after the RPM reducing step, the RPM of the drive motor for a predetermined set time, RPM maintenance step of maintaining the set RPM; and a change width judgment step of re-determining whether the change range of the current of the drive motor is greater than or equal to the reference change range after the set time has elapsed.

In addition, when the change range of the current of the drive motor determined in the change range judgment step is lower than the reference change range, the RPM of the drive motor is increased to the PRM before being reduced in the RPM decrease step, further comprising an RPM increase step. To, a hermetic compressor control method can be provided.

In addition, a hermetic compressor control method may be provided in which the RPM maintaining step is performed when the change width of the current of the driving motor determined in the change width determination step is greater than or equal to the reference change width.

According to one aspect of the present invention, since the RPM of the drive motor is reduced, the change range of the current of the drive motor is reduced, and the hunting phenomenon can be eliminated, it is possible to prevent the freezing capacity of the refrigeration equipment from deteriorating.

1 is a perspective view of a hermetic compressor according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the hermetic compressor taken along line AA′ of FIG. 1 .
Figure 3 is a graph showing the current and RPM of the drive motor of the hermetic compressor of Figure 1;
4 is a graph showing waveforms when the current of the driving motor of the hermetic compressor of FIG. 1 is a hunting phenomenon.
5 is a flowchart of a hermetic compressor control method according to an embodiment of the present invention.

Hereinafter, specific embodiments for implementing the technical idea of the present invention will be described in detail with reference to the drawings.

In addition, in the description of the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

In addition, when a component is referred to as being 'connected', 'supported', or 'moved' to another component, it is understood that it may be directly connected to, supported, or moved to the other component, but other components may exist in the middle. It should be.

Terms used in this specification are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In addition, in this specification, expressions such as upper, lower, side, etc. are described based on the drawings, and it is made clear in advance that they may be expressed differently if the direction of the object is changed. For the same reason, some components in the accompanying drawings are exaggerated, omitted, or schematically illustrated, and the size of each component does not entirely reflect the actual size.

In addition, terms including ordinal numbers, such as first and second, may be used to describe various components, but the components are not limited by these terms. These terms are only used to distinguish one component from another.

As used herein, the meaning of "comprising" specifies specific characteristics, regions, integers, steps, operations, elements, and/or components, and other specific characteristics, regions, integers, steps, operations, elements, elements, and/or groups. does not exclude the presence or addition of

Hereinafter, a hermetic compressor 1 according to an embodiment of the present invention will be described with reference to the drawings.

Referring to FIGS. 1 and 2 , the hermetic compressor 1 may compress fluid. The hermetic compressor 1 may be mounted in a refrigeration facility. For example, the hermetic compressor 1 may be used to compress refrigerants used in refrigeration facilities such as refrigerators and water purifiers. The hermetic compressor 1 may include a hermetic container 100, a compression unit 200, a drive motor 300, and a controller 400.

The airtight container 100 may provide an airtight space in which the compression unit 200 and the driving motor 300 are accommodated. The airtight container 100 may include an upper shell 110 and a lower shell 120 that are coupled to each other to form an airtight space in which the compression unit 200 and the driving motor 300 are accommodated.

The compression unit 200 may compress the refrigerant by receiving driving force from the driving motor 300 . The compression unit 200 may include a compression chamber 210 in which the refrigerant is compressed and a piston (not shown) pressurizing the refrigerant in the compression chamber 210 .

The driving motor 300 may provide power to the compression unit 200 so that the piston can reciprocate inside the compression chamber 210 . For example, the drive motor 300 may include a three-phase motor, but is not limited thereto. The drive motor 300 may include a stator 310 and a rotor 320 .

The stator 310 may generate an electromagnetic field that interacts with the rotor 320 . An empty space for accommodating the rotor 320 may be formed at the center of the stator 310 . In addition, a slot in which a coil can be wound may be provided inside the stator 310, and a plurality of such slots may be provided. These plurality of slots may be spaced apart from each other along the circumferential direction of the stator 310 inside the stator 310 .

The rotor 320 may rotate by electromagnetically interacting with the stator 310 and transmit power to the compression unit 200 . The rotor 320 may be located in a space formed at the center of the stator 310 . Also, poles may be provided in the rotor 320, and a plurality of poles may be provided. The plurality of poles may be spaced apart from each other along the circumferential direction of the rotor 320 and may be disposed inside the plurality of slots in the radial direction.

The controller 400 may control the driving motor 300 . In addition, the controller 400 may control the driving motor 300 by detecting a variation range of the current of the driving motor 300 in order to eliminate the hunting phenomenon. The hunting phenomenon is a phenomenon that occurs in a refrigeration facility and may mean a phenomenon in which at least one of a load, temperature, voltage, and current of the refrigeration facility vibrates rapidly. In addition, when the hunting phenomenon occurs, the current of the drive motor 300 may also vibrate. The controller 400 may measure the current in real time by calculating a feedback signal (one of three phases or all three phases) fed back when the driving motor 300 is driven by an IC within the controller 400 . In addition, the controller 400 may detect a current change range for a predetermined reference time period and compare the sensed current change range with the reference change range. In addition, the controller 400 may determine a hunting phenomenon when the change range of the current of the drive motor 300 is greater than or equal to a preset standard change range for a reference time.

3 and 4 , the controller 400 controls the operation of the drive motor 300 when the range of change in the current of the drive motor 300 due to the hunting phenomenon is greater than or equal to the preset standard range of change for a predetermined reference time. The drive motor 300 may be controlled so that the RPM decreases. For example, in the case of a household water purifier, the reference time may be 15 seconds or more and 25 seconds or less, and the reference change width may be ± 65 mA or more ± 75 m or less, but is not limited thereto and may be formed differently depending on the cooling facility. Also, as shown in FIG. 4 , the controller 400 may decrease the RPM of the drive motor 300 when 100 mA is changed for 19 seconds.

In addition, the controller 400 may control the drive motor 300 so that the reduced RPM of the drive motor 300 is maintained at the preset set RPM for a predetermined set time. The set time may be formed differently depending on the cooling facility. For example, when the cooling facility is a water purifier, the setting time may be 2 minutes.

The controller 400 controls the RPM of the drive motor 300 to increase when the change range of the current of the drive motor 300 is lower than the reference change range after the set time has elapsed and the RPM of the drive motor 300 decreases. The driving motor 300 may be controlled to be driven at RPM. In other words, the controller 400 may control the RPM of the drive motor 300 to increase when the hunting phenomenon is removed and the refrigeration facility operates normally.

Hereinafter, the operation and effect of the hermetic compressor 1 according to an embodiment of the present invention will be described.

When a hunting phenomenon occurs, the controller 400 of the hermetic compressor 1 according to an embodiment of the present invention can reduce the RPM of the drive motor 300 to eliminate the hunting phenomenon, so that the cooling capacity of the refrigeration equipment is reduced. that can be prevented In other words, the controller 400 can monitor the conditions of the hermetic compressor 1 and the refrigeration equipment in real time to detect and remove an abnormal operation such as a hunting state.

Hereinafter, a hermetic compressor control method according to an embodiment of the present invention will be described with reference to FIG. 5 .

The hermetic compressor control method may include a drive step (S100), a change width determination step (S200), an RPM decrease step (S300), an RPM maintenance step (S400), a change width judgment step (S500), and an RPM increase step (S600). there is.

The driving step (S100) is a step in which the driving motor 300 included in the hermetic compressor 1 is driven to compress the refrigerant. In other words, in the driving step (S100), current may be applied to the driving motor 300.

The change width determination step (S200) is a step in which the controller 400 determines whether the change range of the current of the drive motor 300 is greater than or equal to a preset standard change width for a predetermined reference time. In addition, in the change width determination step (S200), the controller 400 may determine the change width through current of any one of the three phases of the motor.

The RPM reduction step (S300) is a step in which the RPM of the drive motor 300 is reduced to a preset set RPM when the change range of the current of the drive motor 300 is greater than or equal to the reference change range for a reference time. In other words, the controller 400 may control the driving motor 300 so that the RPM of the driving motor 300 is reduced to the set RPM.

The RPM maintenance step (S400) is a step in which the RPM of the drive motor 300 is maintained at the set RPM for a predetermined set time after the RPM decrease step (S300).

The change range judgment step (S500) is a step of re-determining whether the change range of the current of the driving motor 300 is greater than or equal to the reference change range after the set time has elapsed. In other words, the change range judgment step (S500) is a step of determining whether the hunting phenomenon has been removed. When the variation range of the current of the drive motor 300 determined in the variation range judgment step (S500) is greater than or equal to the reference variation range, the RPM maintaining operation (S400) may be re-performed.

In the RPM increase step (S600), when the change range of the current of the drive motor 300 determined in the change range judgment step (S500) is lower than the reference change range, the RPM of the drive motor 300 is reduced in the RPM decrease step (S300). This step is increased to the previous PRM.

Although the embodiments of the present invention have been described as specific embodiments, this is merely an example, and the present invention is not limited thereto, and should be construed as having the widest scope according to the technical spirit disclosed herein. A person skilled in the art may implement a pattern of a shape not indicated by combining/substituting the disclosed embodiments, but this also does not deviate from the scope of the present invention. In addition, those skilled in the art can easily change or modify the disclosed embodiments based on this specification, and it is clear that such changes or modifications also fall within the scope of the present invention.

1: hermetic compressor 100: hermetic container
110: upper shell 120: lower shell
200: compression unit 210: compression chamber
300: drive motor 400: controller
S100: drive step S200: decision step
S300: RPM reduction step S400: RPM maintenance step
S500: change width judgment step S600: RPM increase step

Claims (8)

An airtight container including a lower shell and an upper shell that can be coupled to each other to form an airtight space therein;
a compression unit accommodated in the closed space and compressing the refrigerant;
a driving motor providing a driving force to the compression unit; and
A controller for controlling the driving motor;
The controller,
Controlling the drive motor so that the RPM of the drive motor is reduced when the change range of the current of the drive motor is greater than or equal to a preset reference change range for a predetermined reference time.
hermetic compressor. According to claim 1,
The controller,
Controlling the drive motor so that the reduced RPM of the drive motor is maintained at a preset set RPM for a predetermined set time,
hermetic compressor According to claim 2,
The controller,
After the set time has elapsed, when the change range of the current of the drive motor is lower than the reference change range, the RPM of the drive motor is increased so that the drive motor is driven at the RPM before the RPM of the drive motor is decreased. to control,
hermetic compressor. A driving step of driving a driving motor included in the hermetic compressor to compress the refrigerant;
a change width determination step in which the controller determines whether the change range of the current of the driving motor is greater than or equal to a preset reference change range for a predetermined reference time; and
When the change range of the current of the drive motor is formed to be greater than or equal to the reference change range during the reference time, an RPM reduction step of reducing the RPM of the drive motor to a preset set RPM.
Hermetic compressor control method. According to claim 4,
The drive motor includes a three-phase motor,
In the variation width determination step, the controller determines the variation range through a current of any one of the three phases of the motor.
Hermetic compressor control method. According to claim 4,
After the RPM reducing step, the RPM of the drive motor is maintained at the set RPM for a predetermined set time; and
Further comprising a change width judgment step of re-determining whether the change range of the current of the drive motor is equal to or greater than the reference change range after the set time has elapsed.
Hermetic compressor control method. According to claim 6,
When the change range of the current of the drive motor determined in the change range judgment step is lower than the reference change range, the RPM of the drive motor is increased to the PRM before being reduced in the RPM decrease step Further comprising an RPM increase step,
Hermetic compressor control method. According to claim 6,
When the change width of the current of the drive motor determined in the change width judgment step is greater than or equal to the reference change width, the RPM maintaining step is performed.
Hermetic compressor control method.

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